It is recognized that providing a dressing that promotes healing without scab formation is desirable in wound treatment. In addition, the removal of excess wound exudates is important to promote wound healing and to prevent the breakdown of skin surrounding the wound due to maceration.
Many different types of dressings are commercially available. These commonly include dressings containing gauze, foams, sponges, cotton, wools or other fibrous materials. Gauze and other fibrous materials, while capable of absorbing wound exudate can create problems in wound care because of the tendency of these fibrous materials to be engulfed or entrapped by the newly formed tissue that grows into the dressing. As a result, when these fibrous wound dressings are removed newly formed tissues can be damaged and torn. The other commonly used materials for removing exudates in wound dressings include granules and pastes. Similarly, these are frequently difficult to remove from the wound after hydration by the exudate and typically require flushing with a liquid. Further, these materials are limited in the amount of exudate they can absorb.
U.S. Pat. No. 4,551,490 describes an adhesive composition useful with ostomy and incontinent appliances and which has also been used in adhesive bandages. The composition consists of a homogeneous mixture of polyisobutylene, styrene random or block-type copolymer, mineral oil, soluble hydrocolloid gum, water swellable cohesive strengthening agent and a tackifier. This composition has limited exudate absorption capacity and requires a tackifier for its intended use as an adhesive composition.
U.S. Ser. No. 990,719 filed Dec. 15, 1992 which is commonly owned by the assignee of the present invention teaches improved wound fillers having high absorption capabilities. The wound filler is preferably comprised of from about 25% to 75% by weight of a polymer matrix and 25% to 75% by weight absorbing powers. The disclosures of this application are incorporated herein by reference.